Tropical forest tree is source of new mosquito repellent as effective as DEET

Isolongifolenone, a natural compound found in the Tauroniro tree (Humiria balsamifera) of South America, has been identified as an effective deterrent of mosquitoes and ticks, report researchers writing in the latest issue of Journal of Medical Entomology.

Derivatives of the compound have long been used as fragrances in cosmetics, perfumes, deodorants, and paper products, but new processing methods may make it as inexpensive to produce as DEET, a potent and widely available synthetic insect repellent that works by blocking the aroma of human sweat.

The authors, led by Aijun Zhang of the USDA’s Invasive Insect Biocontrol and Behavior Laboratory, found that isolongifolenone deters the biting of the mosquitoes Aedes aegypti and Anopheles stephensi “more effectively than the widely used synthetic chemical repellent N,N-diethyl-3-methyl benzamide (DEET) in laboratory bioassays” and repels blacklegged ticks and lone star ticks “as effectively as DEET”.

Since “isolongifolenone is easily synthesized from inexpensive turpentine oil feedstock,” the authors write, “we are therefore confident that the compound has significant potential as an inexpensive and safe repellent for protection of large human populations against blood-feeding arthropods.”

Tauroniro — which is also known as Bastard bulletwood, Oloroso, Couramira, or Turanira — is found in marshy forests in the Guianas, Colombia, Venezuela, and the Brazilian Amazon, according to the U.S. Forest Service.